The present invention relates to electrically controlled electro-optical devices that enable the display of images, directly by transmission on a panel that modulates light or indirectly by projection on a screen. The invention relates more particularly to devices making use of a liquid crystal placed between two crossed polarizers and having a twisted nematic structure when there is no modulating electrical field. In this configuration, the transparency can be made to decrease when the liquid crystal cell is subjected to an increasing electrical voltage. The displayed image has a defect of uniformity that depends on the angular conditions of observation. To reduce this drawback, the invention proposes to associate one or more compensating blades or plates, formed by a uniaxial birefringent optical medium, with the liquid crystal layer, the unit thus formed being placed between the two crossed polarizers. This technique can be used to obtain a far more homogeneous contrast ratio in a wider angle of observation.